Title: Infiltration of H2SO4 through Concrete with and without Carbon Fiber-Reinforced Polymer Confinement
Author(s): Yail J. Kim and Yongcheng Ji
Publication: Materials Journal
Appears on pages(s): 67-77
Keywords: carbon fiber-reinforced polymer (CFRP); infiltration; strengthening; sulfuric acid
This paper presents the infiltration of sulfuric acid (H2SO4) through concrete confined with carbon fiber-reinforced polymer (CFRP) sheets. Despite the popularity of such a rehabilitation method in upgrading the strength and ductility of existing reinforced concrete columns, scarce information is available when these members are exposed to H2SO4 as a result of changes in service environments after strengthening. In an experimental comparative study alongside plain concrete, the efficacy of CFRP confinement is elaborated in the context of durability. Concrete specimens with and without CFRP confinement are immersed in a 5% solution for up to 6 weeks and are used to examine their physical and chemical responses. In the concrete subjected to the acid, H2SO4 dissolves the cement binder, alters surface-level pH values, and lowers the electrical resistivity of the plain concrete. Although the resin of the CFRP allows the ingress of H2SO4, the influence was not as significant as that of its plain counterpart. The CFRP system impedes the progression of chlorides through the conditioned concrete, which is beneficial in mitigating the potential corrosion damage of strengthened concrete members, preserves the integrity of the conditioned concrete, and lessens the absorption and effective diffusivity of H2SO4.